The mitral valve exhibits two types of pathologies: regurgitation and stenosis. Regurgitation is the more common of the two defects. Either defect may be treated by a surgical repair. Under certain conditions, the mitral valve must be replaced. A standard surgical approach to mitral valve replacement requires cutting open the left side of the heart to access the native mitral valve.
US 2008/0071363 to Tuval et al, describe prosthesis for implantation at a native semilunar valve of a native valve complex via in at least one embodiment a transapical approach. The prosthesis includes a distal fixation member, configured to be positioned in a downstream artery, and shaped so as to define exactly three proximal engagement arms that are configured to be positioned at least partially within respective ones of semilunar sinuses, and, in combination, to apply, to tissue that defines the semilunar sinuses, a first axial force directed toward a ventricle. The prosthesis further includes a proximal fixation member configured to be positioned at least partially on a ventricular side of the native semilunar valve, and to apply, to the ventricular side of the native valve complex, a second axial force directed toward the downstream artery, such that application of the first and second forces couples the prosthesis to the native valve complex.
US 2009/0276040 to Rowe et al. describe a prosthetic mitral valve assembly and method of inserting the same via in at least one embodiment a transapical approach. In certain embodiments, the prosthetic mitral valve assembly includes a stent or outer frame having a flared upper end and a tapered portion to fit the contours of the native mitral valve.
US 2010/0217382 to Chau et al. describe a prosthetic mitral valve assembly and method of inserting the same via in at least one embodiment a transapical approach. The prosthetic mitral valve assembly includes a stent frame and valve combination with an upper anchoring portion being positionable above the annulus of the mitral valve within the left atrium. The upper anchoring portion of the stent frame may include a lattice structure with cells left intentionally disconnected from adjacent cells and bent outwardly to create prongs for anchoring the valve assembly.
US 2009/0005863 to Goetz et al. describe a replacement valve for implantation centrally within the orifice of a malfunctioning native heart valve. The valve is designed for minimally invasive entry through an intercostal opening in the chest of a patient and an opening in the apex of the human heart. The replacement valve includes either a separate anchor or a combined anchor that folds around the malfunctioning native valve leaflets, sandwiching them in a manner so as to anchor the replacement valve at a desired location.
US 2009/0216312 to Straubinger et al. describe a stent for the positioning and anchoring of a valvular prosthesis in an implantation site in the heart of a patient. Specifically, Straubinger relates to an expandable stent for an endoprosthesis having positioning arches and retaining arches, whereby at least one positioning arch is connected to at least one retaining arch via a first connecting web. The stent also includes at least one auxiliary retaining arch that connects the respective arms of the at least one retaining arch connected to the at least one positioning arch.
US 2008/0255660 to Guyenot et describe a medical device for treating a heart valve insufficiency with an endoprosthesis that can be introduced into a patient's body and expanded to secure a heart valve prosthesis in the patient's aorta. The endoprosthesis may have a plurality of positioning arches configured to be positioned with respect to a patient's aorta connected to and positioned above a plurality of retaining arches to support a heart valve prosthesis.
Due to the different physical characteristics of the mitral valve as compared to other valves such as the pulmonary and aortic valves, percutaneous implantation of a prosthetic valve in the mitral position has its own unique requirements for valve replacement. There is a continued need within the art to provide improved mitral valve replacement devices that may be delivered by minimally invasive techniques and that accommodate the structure of the heart.